Table 5 - COMPARISON OF PEAK DATES AND PEAK NUMBERS 
1953 thru 1960 Fall Seasons 
_-s=“‘(<ar’” <SU*pper”Miss.: Louisa : Keithsburg : Gardner: Batchtown :  Calhom : ENTIRE : 
: Refuge | Unit Unit Unit 3 Unit 3 Unit : AREA : 
Peak Dates : : 
Earliest Oct. 12 Nov. 2 Nov. 9 : Nov. 16 ; Oct. 26 Nov. 30 Oct. 26 
Latest Oct. 30 Dec. 14 : Dec. 14 Nov. 30 Dec. 28 Dec. 28 Dec. 28 
Average : Nov. 2 Nov. 16 Nov. 30 : Nov. 30 Nov. 9-16 Dec. 7 Dec. 7 
: : : : ) : : 
Peak Numbers : 3 : : : : 3 : 
Lowest : 160 , 845 h5 ,672 2,170 7,611 : 42 ,300 203 ,200 406 ,172 
Highest 345 ,280 251,150 135,150 35,454 :1,001,800 : 714 ,800 1,379,965 
Average : 240,720 135,810 : 76,280 : 22,665 : 218,550 he ,600 . 767,140 
; : : ; 3 : : : 

(Dates shown are last day of the week.) 
Note: Peak numbers in the "Entire Area" column represent populations present over the 550 miles of the 
Mississippi River ON THE SAME WEEK; and are not necessarily the combined totals of the individual 
areas, each of which may have peaked at a different time, either earlier or later. 
Note there is a difference of only one week in the average peak date on the Upper Mississippi Refuge and 
the Batchtown Unit of Mark Twain Refuge, although these areas are 250 miles apart. There are two reasons 
for this. First, Batchtown picks up ducks moving in from the northwest, and reaching the Mississippi 
River south of the Upper Mississippi Refuge. Batchtown also often has an earlier build-up than Calhoun 
Unit, which is only a few miles away on the Illinois River. There is some interchange of birds between 
these unite in the fall. Batchtown is mostly quiet backwater which freezes with the first cold snap, at 
which time ducks move east across the ridge of Calhoun County to the Calhoun Unit, which remains open 
longer. 
